/*
 * This file is part of the OregonCore Project. See AUTHORS file for Copyright information
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include "ModelInstance.h"
#include "WorldModel.h"
#include "MapTree.h"
#include "VMapDefinitions.h"

using G3D::Vector3;
using G3D::Ray;

namespace VMAP
{
ModelInstance::ModelInstance(const ModelSpawn& spawn, WorldModel* model): ModelSpawn(spawn), iModel(model)
{
    iInvRot = G3D::Matrix3::fromEulerAnglesZYX(G3D::pi() * iRot.y / 180.f, G3D::pi() * iRot.x / 180.f, G3D::pi() * iRot.z / 180.f).inverse();
    iInvScale = 1.f / iScale;
}

bool ModelInstance::intersectRay(const G3D::Ray& pRay, float& pMaxDist, bool pStopAtFirstHit) const
{
    if (!iModel)
        return false;

    float time = pRay.intersectionTime(iBound);
    if (time == G3D::inf())
        return false;

    // child bounds are defined in object space:
    Vector3 p = iInvRot * (pRay.origin() - iPos) * iInvScale;
    Ray modRay(p, iInvRot * pRay.direction());
    float distance = pMaxDist * iInvScale;
    bool hit = iModel->IntersectRay(modRay, distance, pStopAtFirstHit);
    if (hit)
    {
        distance *= iScale;
        pMaxDist = distance;
    }
    return hit;
}

void ModelInstance::intersectPoint(const G3D::Vector3& p, AreaInfo& info) const
{
    if (!iModel)
    {
        #ifdef VMAP_DEBUG
            std::cout << "<object not loaded>\n";
        #endif
        return;
    }

    // M2 files don't contain area info, only WMO files
    if (flags & MOD_M2)
        return;
    if (!iBound.contains(p))
        return;
    // child bounds are defined in object space:
    Vector3 pModel = iInvRot * (p - iPos) * iInvScale;
    Vector3 zDirModel = iInvRot * Vector3(0.f, 0.f, -1.f);
    float zDist;
    if (iModel->IntersectPoint(pModel, zDirModel, zDist, info))
    {
        Vector3 modelGround = pModel + zDist * zDirModel;
        // Transform back to world space. Note that:
        // Mat * vec == vec * Mat.transpose()
        // and for rotation matrices: Mat.inverse() == Mat.transpose()
        float world_Z = ((modelGround * iInvRot) * iScale + iPos).z;
        if (info.ground_Z < world_Z)
        {
            info.ground_Z = world_Z;
            info.adtId = adtId;
        }
    }
}

bool ModelInstance::GetLocationInfo(const G3D::Vector3& p, LocationInfo& info) const
{
    if (!iModel)
    {
        #ifdef VMAP_DEBUG
            std::cout << "<object not loaded>\n";
        #endif
        return false;
    }

    // M2 files don't contain area info, only WMO files
    if (flags & MOD_M2)
        return false;
    if (!iBound.contains(p))
        return false;
    // child bounds are defined in object space:
    Vector3 pModel = iInvRot * (p - iPos) * iInvScale;
    Vector3 zDirModel = iInvRot * Vector3(0.f, 0.f, -1.f);
    float zDist;
    if (iModel->GetLocationInfo(pModel, zDirModel, zDist, info))
    {
        Vector3 modelGround = pModel + zDist * zDirModel;
        // Transform back to world space. Note that:
        // Mat * vec == vec * Mat.transpose()
        // and for rotation matrices: Mat.inverse() == Mat.transpose()
        float world_Z = ((modelGround * iInvRot) * iScale + iPos).z;
        if (info.ground_Z < world_Z) // hm...could it be handled automatically with zDist at intersection?
        {
            info.ground_Z = world_Z;
            info.hitInstance = this;
            return true;
        }
    }
    return false;
}

bool ModelInstance::GetLiquidLevel(const G3D::Vector3& p, LocationInfo& info, float& liqHeight) const
{
    // child bounds are defined in object space:
    Vector3 pModel = iInvRot * (p - iPos) * iInvScale;
    //Vector3 zDirModel = iInvRot * Vector3(0.f, 0.f, -1.f);
    float zDist;
    if (info.hitModel->GetLiquidLevel(pModel, zDist))
    {
        // calculate world height (zDist in model coords):
        // assume WMO not tilted (wouldn't make much sense anyway)
        liqHeight = zDist * iScale + iPos.z;
        return true;
    }
    return false;
}

bool ModelSpawn::readFromFile(FILE* rf, ModelSpawn& spawn)
{
    uint32 check = 0, nameLen;
    check += fread(&spawn.flags, sizeof(uint32), 1, rf);
    // EoF?
    if (!check)
    {
        if (ferror(rf))
            std::cout << "Error reading ModelSpawn!\n";
        return false;
    }
    check += fread(&spawn.adtId, sizeof(uint16), 1, rf);
    check += fread(&spawn.ID, sizeof(uint32), 1, rf);
    check += fread(&spawn.iPos, sizeof(float), 3, rf);
    check += fread(&spawn.iRot, sizeof(float), 3, rf);
    check += fread(&spawn.iScale, sizeof(float), 1, rf);
    bool has_bound = (spawn.flags & MOD_HAS_BOUND);
    if (has_bound) // only WMOs have bound in MPQ, only available after computation
    {
        Vector3 bLow, bHigh;
        check += fread(&bLow, sizeof(float), 3, rf);
        check += fread(&bHigh, sizeof(float), 3, rf);
        spawn.iBound = G3D::AABox(bLow, bHigh);
    }
    check += fread(&nameLen, sizeof(uint32), 1, rf);
    if (check != uint32(has_bound ? 17 : 11))
    {
        std::cout << "Error reading ModelSpawn!\n";
        return false;
    }
    char nameBuff[500];
    if (nameLen > 500) // file names should never be that long, must be file error
    {
        std::cout << "Error reading ModelSpawn, file name too long!\n";
        return false;
    }
    check = fread(nameBuff, sizeof(char), nameLen, rf);
    if (check != nameLen)
    {
        std::cout << "Error reading ModelSpawn!\n";
        return false;
    }
    spawn.name = std::string(nameBuff, nameLen);
    return true;
}

bool ModelSpawn::writeToFile(FILE* wf, const ModelSpawn& spawn)
{
    uint32 check = 0;
    check += fwrite(&spawn.flags, sizeof(uint32), 1, wf);
    check += fwrite(&spawn.adtId, sizeof(uint16), 1, wf);
    check += fwrite(&spawn.ID, sizeof(uint32), 1, wf);
    check += fwrite(&spawn.iPos, sizeof(float), 3, wf);
    check += fwrite(&spawn.iRot, sizeof(float), 3, wf);
    check += fwrite(&spawn.iScale, sizeof(float), 1, wf);
    bool has_bound = (spawn.flags & MOD_HAS_BOUND);
    if (has_bound) // only WMOs have bound in MPQ, only available after computation
    {
        check += fwrite(&spawn.iBound.low(), sizeof(float), 3, wf);
        check += fwrite(&spawn.iBound.high(), sizeof(float), 3, wf);
    }
    uint32 nameLen = spawn.name.length();
    check += fwrite(&nameLen, sizeof(uint32), 1, wf);
    if (check != uint32(has_bound ? 17 : 11)) return false;
    check = fwrite(spawn.name.c_str(), sizeof(char), nameLen, wf);
    if (check != nameLen) return false;
    return true;
}

}
